polymicrogyria
Pronunciation: pol-ee-my-crow-JY-ree-ah
A cortical malformation characterized by abnormally small and numerous brain folds, creating an irregular brain surface.
Full Definition
Polymicrogyria is a disorder of cortical development in which the normal pattern of brain folds is replaced by many small, irregular gyri separated by shallow sulci. This malformation results from abnormal late neuronal migration or early cortical organization during fetal development. The condition can be focal (affecting specific brain regions) or diffuse (widespread), and may be unilateral or bilateral. Clinical presentations vary widely depending on the location and extent of involvement, ranging from mild learning difficulties to severe developmental delays and seizures. Polymicrogyria can be associated with various genetic syndromes or may occur as an isolated finding.
Usage
Usage note: Often abbreviated as PMG in clinical documentation.
In Context
- "The patient exhibited bilateral perisylvian polymicrogyria with characteristic pseudobulbar signs." — Neurological examination report
- "High-resolution MRI revealed focal polymicrogyria in the right parietal region." — Diagnostic imaging report